The 25-year-lock has a well-founded reputation for robust play and his ability to prove disruptive could cause South Africa problems.
Lavanini, who came off the bench last weekend, set a new record of six yellow cards in Pumas tests last year.
He is the only change to the starting XV as he takes the place of Matias Alemanno.
Saturday’s match marks the home debut for new coach Mario Ledesma, who added reinforcements to the squad after returning from Durban and has named two to the bench.
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French-based hooker Facundo Bosch will be among the replacements and inside centre Jeronimo de la Fuente is also back on the reserve bench after injury.
Bosch is one of only two Europe-based players in the Argentina squad. The other is Saracens tighthead Juan Figallo.
Team: 15-Emiliano Boffelli, 14-Bautista Delguy, 13-Matias Moroni, 12-Bautista Ezcurra, 11-Ramiro Moyano, 10-Nicolas Sanchez, 9-Gonzalo Bertranou, 8-Javier Ortega Desio, 7-Marcos Kremer, 6-Pablo Matera, 5-Tomas Lavanini, 4-Guido Petti, 3-Juan Figallo, 2-Agustin Creevy (captain), 1-Nahuel Tetaz Chaparro
Replacements: 16-Facundo Bosch, 17-Santiago Garcia Botta, 18-Santiago Medrano, 19-Matías Alemanno, 20-Tomas Lezana, 21-Tomas Cubelli, 22-Jeronimo de la Fuente, 23-Juan Cruz Mallia
(Reporting by Mark Gleeson in Cape Town; Editing by Ed Osmond)
